Method WriteHex

src/openboardview/confparse.cpp:565–569

	return WriteStr(key, v);
};
bool Confparse::WriteHex(const char *key, uint32_t value) {
	char v[20];
	snprintf(v, sizeof(v), "0x%08x", value);
	return WriteStr(key, v);
};
bool Confparse::WriteFloat(const char *key, double value) {
	char v[20];
	snprintf(v, sizeof(v), "%f", value);